1. Field of the Invention
The present invention generally relates to a control adapter device, and more particularly to a control adapter device to be attached to a control unit having an input control part.
2. Description of the Related Art
As for a control unit including an input control part for allowing the user to execute an inputting maneuver (input control), there are, for example, a keyboard of a personal computer, a controller for a television game machine, and a control part used in controlling computer-controlled conveying machines or industrial robots.
These types of control units are able to conduct wireless transmission of signals by attaching thereto a control adapter device including a transmission part using, for example, electric waves, infrared rays, and/or light. A conventional example is shown in Japanese Laid-Open Patent Application No. 2002-73259.
The control adapter device is provided with an engagement mechanism for engagement with a wall face of the control unit. The engagement mechanism is attached to the control unit in a manner that the engagement mechanism can separate from the wall face of the control unit when an engagement lever of the engagement mechanism is pressed in an engagement disengaging direction (direction disengaging the control adapter device from the control unit).
There is a growing demand for a size-reduced and lightweight control adapter device that is to be mounted to the control unit in the aforementioned manner. For example, the control adapter device may have an antenna or a substrate including a transmission circuit installed inside of its case. Furthermore, the control adapter device may also have a connector or an engagement mechanism disposed in a space surrounding the substrate.
In order to enable the engagement lever of the engagement mechanism to rotatably move such that the engagement lever will not contact the substrate or the connector, a stopper for restricting the angle of rotation of the rotating engagement lever is arranged at the fulcrum of the rotating engagement lever. The stopper, in the form of a cylindrical rib, has a step portion that is disposed in the vicinity of the rotation center so that the step portion is contacted by the engagement lever to thereby restrict the rotation angle of the engagement lever.
The engagement lever, being a resin molded component, may lack strength and be susceptible to deformation when the radial thickness of the engagement lever is uniformly formed for improving moldability.
Therefore, when a pressing force is applied to a press-maneuver part for rotatively moving the engagement lever to the engagement disengaging direction, the engagement lever deforms (bends) when the engagement lever contacts the step portion of the cylindrical rib (stopper) formed in the periphery of the rotation center, and adversely affects the maneuvering feel of the press-maneuver part.